90 GEOLOGY AND HISTORY 



years of that time, or say six thousand to eight 

 thousand years ago. How long the second conti- 

 nental or palanthropic period continued intact we 

 do not know, but we can scarcely allow it less than 

 two thousand years. Perhaps it was considerably 

 longer. Now on historical evidence produced by 

 Egypt, Chaldea, and other ancient countries in the 

 Mediterranean region, we can trace the neanthropic 

 age continuously back to, say, three thousand years B.C., 

 or nearly five thousand years in all. Adding to this 

 two thousand years for the palanthropic age, we are 

 carried back to a time within one thousand years of 

 the earliest we can assign on geological grounds to 

 the termination of the great glacial period. There- 

 fore, unless we suppose the last continental subsidence 

 to have begun some time before the close of the 

 palanthropic age, and to have continued to some 

 degree into the beginning of the neanthropic, we 

 cannot assign to it a very long time. That it could 

 not have been sudden in the sense of being instan- 

 taneous is evident, because in that case terrestrial 

 denudation of a stupendous character must have 

 ensued, and no animal life except that of mountain 

 tops and elevated table-lands could have escaped its 

 destructive effects, but that it was by no means 

 secular or long-continued is certain. 



Thus we seem shut up to the conclusion that 

 the close of the palanthropic age was marked by 

 great geological vicissitudes of the character of sub- 

 mergence, leading primarily to vast destruction of 



